Pilot controlled diaphragm valve



March 12, 1940. D. G. GRISWOLD PILOT CONTROLLED DIAPHRAGM VALVE FiledMay 17, 1937 7 1 4 4 $51M 4 5 m M W 5 0 M w w z a; a J 1 W 5 r 1 6 W w JM M. Z Y 3 m MN m J a a W 0 M 1 A, Z Z A 7 2 fi J 3 W z a w a l I v pvlflllll rI/ I III q IA 7 W Z a. a 1 0 a II,

Patented Mar. 12, 1940 PATENT OFFICE 2,193,720 PILOT CONTROLLEDDIAPHRAGM VALVE Donald G. Griswold, Alhambra, Calif., assignor toClayton Manufacturing Company, a corporatlon of California ApplicationMay 17, 1937, Serial No. 143,077

9 Claims. (Cl. 137-139) The invention relates generally to valves andmore particularly to that type of valve in which the main valve is inthe form of a diaphragm which is held in closed position by fluidpressure 6 in a chamber on one side of the valve, the entrance andescape of fluid from the chamber being controlled by an auxiliary orpilot valve.

It is a primary object of this invention to provide a pilot controlleddiaphragm valve which willpositively control a fluid stream of anyvolume or pressure so that the stream is entirely free to flow or ispositively stopped from flowing and which requires only a very smalloperating force for actuation which is not affected by the volume orpressure of the fluid stream being controlled.

More especially it is an object of this invention to provide a valve ofthe type indicated, which requires only a 'very small valve actuatingforce to control a large stream of fluid regardless of the volume andpressure of the stream of fluid to be controlled. It is also an objectof this invention to provide a valve in which the force required tooperate the valve remains constant ll and is not affected in any mannerby the volume or pressureof the fluid to be controlled. It is a 'furtherobject of this invention to provide a valve in which the force requiredto operate the valve remains constant over a period of time and does nottend to stick or require increased force to move it as it ages, wears,or corrodes. I

' Furthermore, it is an object of this invention to provide a valvewhich is positive in operation, that a valve that is either wide open orcompletely closed at any given time and which is incapable of beingcracked partially open and held in that position. In this connection itis also an object of this invention to provide a valve which will notflutter. or oscillate between an open and closed position.

These and-other objects are apparent from the accompanying drawing andthe following description. Referring to the drawing, which is forillustrative p p ses only,

46 Fig. 1 is a longitudinal sectional elevation of a valve embodying oneform of my invention. This form is particularly suitable for controllingfluid inpipes of relatively small diameter.

Fig. 2 is a fragmentary sectional elevation of the valve shown in Fig. 1illustrating the valve in open position.

Fig. 3 is a perspective. view of the va ve disc and disc drive washer ofthe pilot valve.

Fig. 4 is a sectional elevation of a form of the u inventionparticularly suitable for use in controlling fluid in pipes ofrelatively large. diameter. The valve of this invention comprises a maindiaphragm valve member generally indicated by reference letter A, whichis adapted to be closed by the pressure of the fluid being controlled,and 5 to accomplish this there is provided behind the diaphragm what maybe termed a valve chamber.

The entrance and escape of fluid to this chamber, and consequently theoperation of the main diaphragm valve is controlled by a pilot valve, or10 auxiliary valve, generally indicated by reference letter B.

Referring more particularly to the drawing, reference numeral llgenerally indicates a valve body which comprises a fluid intake section12, 15 a central section l3 and a rear, or pilot housing section ll.Interposed between *the sections l2 and i3 is a diaphragm valve memberl5 which also serves to act as a sealing means between the two sections.Between sections i3 and i4 is a gasket 29 I6 of any suitable material.The three sections comprising the valve body are suitably held togetherby screws 11 which extend through openi gsin sections 13 and i4 and arethreaded into the section l2. v

The intake section I2 is provided with an externally threaded inlet l2on which may be threaded a fluid conduit (not shown) which may carry thefluid to be controlled. The section l2 has a passage 20 formed thereinwhich terminates 8 in an opening 2 I .of less diameter. The inner end ofthe p vssage 20 constitutes a valve seat 22 which is adapted'tobeengaged by the diaphragm i5 when the valve is in closed position asshown in Fig. 1. Surrounding the valve seat 22 is an annular recess 23whichis in open communication with an outlet or discharge passage 24 inthe section l2.

The central section I3 is provided with a circular recessed face 26 onits front side, which, 4|)

together with the diaphragm l5 provides a valve chamber 21.Communicating with this chamber is a bore 28 which extends through thecentral section. This section is alsoprovided with what may be termed afluid escape passage 29, the 5 purpose of which will subsequently befully described.

The rear side of the central section l3 has a central circular, hub orraised portion 30 which is surrounded by an annular depressed'portion 6o42. The hub has a machined surface or valve face 3!.-

The pilot housing section or rear section ll has a central bore 34 whichis adapted to ac-' commodate the pilot valve generally indicated by B.Bore 34 terminates at its outer end in a bore 35 of less diameter.Extending through the bore 35 is a rotatably mounted shaft 55 which, atits outer end, extends through the bracket portion 51 of the rearsection H of the valve body.

Mounted on the inner end of the shaft 35 4s a drive washer 35 which hasdrive pins 35 adapted to extend into holes 40 inthe valve disc 4|.Mounted on the shaft 25 is a packing 42 backed by a washer 43.Inter-posed between the drive washer 28 and the washer 45 is acompression spring 44 which serves to press or yieldably hold the valvedisc 4| against themachined face 3| of the central section II of thevalve body. For the purpose of actuating the shaft 25 there is provideda lever arm 45 which has a small counterweight 45 attached at one end.This arm is adJustably flxedly mounted on the shaft 26 by means of theset screw 41. The arm 45 may be actuated by any suitable force operatingthrough the rod 48 or any other suitable connection.

That portion of the bore 24 between the valve disc 4| and the packing 42constitutes a pm;- sure chamber 50 which is under substantially the samepressure as the pressure of the fluid in inlet passage 25. For thepurpose of providing fluid pressure in this chamber 55 a diversionpassage or by-pass, generally indipated by reference numeral 5|, isprovided which establishes open communication between the chamber 20 andthe chamber 55. This passage is comprised of the three passages 52, 52,and 54 in the three sections l2, l3 and M respectively. The diaphragm l5and gasket l5 are apertured at l5 and [5' respectively to permit passageof fluid through theg'by-pass 5|.

For the purpose of controlling the entrance and escape of fluid from thevalve chamber 21 the valve disc 4| is provided with passages 55 and 56'which extend entirely through the valve disc. In actual operation onlyOne of the passages is used and the purpose of providing two pmsages isthat with this construction either "right" or left hand operation of thevalve is possible, as will subsequently be evident.

The valve disc is also provided with a U-shaped passageway 51 which hasan opening 52 on the inner face of the disc in the center thereof, andhas another opening 59 between the inner end of passages 56 and 55' andradially spaced from the central opening 55 a distance equal to thespace between either of the passages 55 and 55 and the central opening58. For the purpose of-..

lubrication, the disc is also provided with the three openings 65 whichin practice are packed with grease.

when the valve is assembled the opening 58 registers with the inner endof passage 29. Either sage 28, the valve chamber 21 is under substantially the same pressur as the pressure of the fluid being controlled.The reason for this is that fluid is diverted from inlet passage 20through the by-pass 5| into chamber 50 and throughthe passages 56 and 28into the valve chamber 21. The fluid escape passage 28 is in a pipeline.

closed by reason of the fact that opening 55 of passage 51 is sealedagainst the face 2|.

The pressure in valve chamber 21 is effective to close the maindiaphragm valve, as shown in Fig. l, by reason of the relatively largearea of the diaphragm against which the fluid pres- :sure is exerted, ascompared with the relatively small area against which fluid pressureoperates on the opposite side of the diaphragm I5, namely an areacorresponding to the cross sectional area of the opening 2|. In thisconnection it is pointed out that the portions of the diaphragm outward-1y of the valve seat 22 are at atmospheric pressure by reason of thecommunicating outlet passage 24.

When it is desired to open the main valve A the lever 45 is rotated adistance sufllcient to cause the opening 59 of passageway 51 to registerwith the passage 28, thereby permitting escape of pressure fluid invalve chamber 21 outwardly through the passages 28, 51 and 25, as mayreadily be seen in Fig. 2. Since the pressure in chamber 21 is therebyreduced to that of atmospheric pressure, the pressure of the fluid inconduit II and passageway 20 is effective to open the main valve A forforcing the diaphragm away from its seat 22.

The counterweight 45 serves to balance the dead weight of the rod 45. Inthis connection it is to be understood that the pilot valve remains inwhatever position it is placed unless some outside force moves it, asfor example a force exerted on the'lever arm 45. The fluid pressure hasno effect toward movement of the pilot valve.

It should be apparent from this description that the main diaphragm Awill be entirely open or entirely closed and cannot be cracked partiallyopen. It should also be apparent that the operation of the pilot valve13 is not affected by the pressure of the fluid being controlled andrequires only a very slight force for its actuation. In this connectionit has been found that valves made similar to the valves shown anddescribed in this application operate succcessfully with only an ounceor two of pressure on the actuating lever when controlling fluidpressure is pounds.

The form of the valve shown in Fig. 1 is particularly designed forcontrolling the entrance of fluid to a tank and the discharge passage 24is shown as discharging directly at the periphery of the valve body.Passage 25 has also been shown as discharging directly at the peripheryof the valve body. The pressure in passages 24 and 29 has thus beendescribed as "atmospheric. However, the passage 24 might be enlarged andthreaded to accommodate a discharge conduit in the event that the valveis located at some point not directly over a receptacle, such as a tank,as would be the case if the valve were used Also the outlet of passage25 might be connected to the discharge passage. In such a case thepressure would necessarily be greater than atmospheric" in each case.This construction is shown in a modified form of valve in Fig. 4.

In Fig. 4 there is illustrated a form of valve which is particularlyadapted for use on pipes of relatively large diameter as compared topipes upon which the valve shown in Fig. l is adapted to be used. Thisvalve comprises a main valve A and pilot valve B as in the other form ofvalve.

Referring particularlyv to Fig. 4, reference numeral 62 generallyindicates a main valve At the opposite end of the section 63 there is.

provided an outlet portion 69 internally threaded at 69' and forming thedischarge passage 10. Substantially surrounding the valve seat 68 is acircular recess H which is in open communication with the dischargepassage 10.

Secured to the section 63 by means of suitable screws 13 is the section64. Interposed between the two sections 63 and 64 and acting as asealing means therebetween is the diaphragm member 14 which correspondsto the diaphragm IS in Fig. 1. Behind the diaphragm the member 64 isrecessed at 15 to provide what may be termed a valve chamber 18 which isformed by the diaphragm and the recessed portion of the member 64. Thesection 64 is provided with a central opening TI therethrough whichestablishes communication between the valve chamber 16 on the one sideof the member 64 and a plate 18" on the other side. 7

The plate 18 and the member l4 are secured to the rear face of themember 64 by means of suitable screws, one of which appears at H, in amanner similar to the way in which the sections 13 and I4 are secured tothe section I! of Fig. 1. Suitable gaskets (not shown), such asonesimilar to the gasket H5 in Fig. 1, are interposed between the abovementioned members. The section I4 is in all respects similar to thesection I4 of Fig. 1, except that it is shownturned at 180 degrees tothe position it is shown in in Fig. 1, and except for the fact that thebracket member 31 has also been eliminated. The pilot valve structureand connecting parts are the same as in Fig. 1. e

The plate 18 is provided with a passageway 19 therethrough and is alsoprovided with a fluid' escape passage 80. These passages are similar tothe passages 28 and 29 of Fig. 1. In this form of the invention however,passage 80 terminates at its outer end in registration with a passage 8|in the member 64. The passage 3| communicates with passage 82 in member63 which has its out- I let in discharge passage III of outlet portion69 of section '63. The diaphragm 14 is suitably apertured at 14' so asnot to obstruct passage of fluid from passage 8| to passage 82. Thus thefluid escape passage from chamber I6 communicates with the dischargepassage .10 of the section 63. I

For providing fluid pressure in the chamber 50 of the section 14 for thepurpose of closing the valve A a by-pass means 85 is provided. By

'reason of the fact that the diiierence in pressure into the restrictedportion of passage 66.. This tube is mounted in the passage 81 in thesection 63 in any suitable manner, as by brazing. A passage whichregisters with passage 81 at one end and which registers with passage 54at .its other end is provided in the section 64. The diaphragm I4 isalso suitably apertured at 14" so as not to prevent passage of fluidfrom passage 81 to passage 88. By this construction it is possible toutilize the velocity of flow of incoming fluid through the opening 61when the valve is in open position in order to secure maximum pressurein the chamber 50. His thus possible to operate, that is, to close thisvalve against the incoming fluid even though the difference in pressurebetween chambers 66 and I0 is slight.

With this type of valve, wherein the valve seat 68 is of relativelylarge diameter as compared with the valve seat in smaller forms of thevalve,

it has been found advisable to reinforce the diaphragm with a renewabledisc valve member in Figs 1 and 2, the pilot valve B of Fig. 4 being inall respects similar to the pilot valve B of Fig. 1.

I claim as my invention:

1. A pilot valve mechanism for controlling a diaphragm type valvecomprising: a valve casing having a pressure chamber formed therein; apassageway in said casing for admitting fluid under pressure into saidpressure chamber; and

- a pilot valve seated against one wall of said pressure chamber forcontrolling the flow of pressure fluid from said chamber to a diaphragmvalve, said wall having a port extending therethrough for the passage offluid to and from said diaphragm valve, said pilot valve having a pairof spaced passageways extending therethrough, each adapted to registerwith said port to permit flow of pressure fluid from said pressurechamber to said diaphragm valve upon shifting of said pilot valve inopposite directions from a given position, said pilot valve also havinga passageway for registering with sai'l port to permit .said fluidtoflow from said diaphragm valve.

2. A pilot valve mechanism for controlling a diaphragm type valvecomprising: a casing having a pressure chamber formed therein; apassageway through said casing for admitting fluid under pressure intosaid pressure chamber; and a pilot valve seated against one wall of saidpressure chamber for controlling the flow of pressure fluid from saidchamber to a diaphragm valve, said wall having a port extendingtherethrough for the passage of fluid to and from saiddiaphragm valve,said pilot valve having a pair of spaced passageways extendingtherethrough, each adapted to register with said port upon shifting ofsaid pilot valve in opposite directions from a given position to permitpressure fluid to flow to said diaphragm valve, said wall having asecond port formed therein and vented to the atmosphere. said pilotvalve having a second passageway arranged to establish communicationbetween said ports when said pilot valve is in said given position topermit said pressure fluid to flow from said diaphragm valve.

3. A valvecomprising, one end section having inlet and outlet openingsand a valve seat intermediate said openings; a second section alignedwith said end section to form a valve chamber; a diaphragm structureclamped between said end and said second sections arranged to provide aseal with said valve seat; a third section aligned with said secondsection and having a pressure chamber formed therein; said secondsection having a port extending therethrough for establishingcommunication between said valve and pressure chambers, said secondsection having a second port therein vented to the atmosphere; means forconducting pressure fluid to said pressure chamber; a pilot valve in'said pressure chamber, said pilot valve having a passageway positionedto register with said first port to admit pressure fluid into said valvechamber to apply pressure to said diaphragm to form a seal with saidseat, said pilot valve having a second passageway for establishingcommunication between said first and second ports to exhaust the fluidfrom said valve chamber to the atmosphere,

able disc secured'thereto for providing a seal with said valve seat; athird section aligned with said second section and having a pressurechamber formed therein; said second section having a port extendingtherethrough for establishing communication between said pressure andvalve chambers, said second section having a second port therein forexhausting spent pressure fluid" from said valve chamber; means forconducting pressure fluid to said pressure chamber; a pilot valve insaid pressure chamber, said pilot valve having a passageway adapted toregister with said first port to admit pressure fluid into said valvechamber to apply pressure to said diaphragm to engage said renewabledisc with said seat to form' a seal, said pilot valve having a secondpassageway for establishing communication between said flrst and secondports to exhaust fluid from said valve chamber, thereby relieving thepressure on said diaphragm and permitting movement thereof away fromsaid seat to establish communication between said inlet and outletopenings.

5. A valve comprising, a housing having inlet and outlet openings; avalve seat intermediate said openings; a diaphragm structure arranged toprovide a seal with said valve seat; a valve chamber in said housing,said diaphragm being arranged so that a portion thereof. forms one sidewall of said valve chamber; a pressure chamber adjacent said valvechamber; a wall separating said pressure and valve chambers, one face ofsaid separating wall confronting said diaphragm and forming another sidewall of said valve chamber, said facehaving a shallow cavity formedtherein to receive pressure fluid foractuation of said diaphragm, saidseparating wall having a port for establishing communication betweensaid pressure an' valve chambers, said separating wall having a secondport for exhausting pressure fluid from said valve chamber; means forconducting pressure fluid to said pressure chamber; a pilot valve discin said pressure chamber seated on the opposite face of said separatingwall, said pilot valve disc having a passageway adapted to register withsaid flrst port to admit pressure fluid from said pressure chamber intosaid valve chamber to actuate said diaphragm to form a seal with saidseat, said pilot valve disc having a second passageway forestablishingcommunication between said first and second ports in saidseparating wall to exhaust pressure fluid from said valve chamber,thereby relieving the pressure on said diaphragm and permitting movementthereof away from said seat to establish communication between saidinlet and outlet'openings.

6. A valve comprising, a housing having inlet and outlet openings; avalve seat intermediate said openings; a diaphragm structure arranged toprovide a seal with said valve seat, said diaphragm extendingtransversely of said housing and arranged to form one side wall or avalve chamber; a pressure chamber adjacent said valve chamber; a wallseparating said pressure and valve chambers, one face of said separatingwall confronting said diaphragm and forming another side wall of saidvalve chamber, said face having a recess therein to receive pressurefluid for actuation of said diaphragm, said separating wall having aport for establishing communication between said pressure and valvechambers, said separating wall having a second port for exhaustingpressurefluid from said valve chamber; means for conducting pressurefluid from the inlet opening to said pressure chambem a pilot valve discin said pressure chamber seated on the opposite face of said separatingwall, said pilot valve disc having a passageway positioned to registerwith said first port to admit pressure fluid from said pressure chamberinto said valve chamber to actuate said diaphragm to form a seal withsaid seat, said pilot valve disc having a second passageway forestablishing communication between said first and second ports in saidseparating wall to exhaust pressure fluid from said valve chamber,thereby relieving the pressure on said diaphragm and permitting movementthereof away from said seat to establish communication between saidinlet and outlet openings.

' 7. A valve comprising, a housing having inlet and outlet openings; avalve seat intermediate said openings; a diaphragm having a renewabledisc secured thereto and arranged to provide a seal with said valveseat, said diaphragm extending transversely of said housing and arrangedto form one side wall of a valve chamber; a pressure chamber adjacentsaid vahe chamber; a wall separating said pressure and valve chambers,one face of said separating wall confronting said diaphragm and forminganother side wall of said valve chamber, said face having a recesstherein to receive pressure fluid for actuation of said diaphragm, saidseparating wall having a port for establishing communication betweensaid pressure and valve chambers, said separating wall having a secondport for exhausting pressure fluid from said valve chamber; means forconducting pressure fluid to said pressure chamber; a pilotvalvedisc insaid pressure chamber-seated on the opposite face oi saidseparating'wall, said pilot valve disc, having a transverse passagewaypositionable to register with said first port to admit pressure fluidfrom said pressure chamber into said valve chamber to actuate saiddiaphragm to form a seal with said seat, said pilot valve disc alsohaving a U-shaped exhaust passageway for establishing communicationbetween said first and second ports insaid separating wall to exhaustpressure fluid from said valve chamber, thereby relievin the pressure onsaid diaphragm and permitting movement thereof away from said seat toestablish communication between said inlet and outlet openings.

8. A valve comprising, one end section having inlet and outlet openingsand a valve seat intermediate said openings; intermediate section meansaligned with said end section to form a-- valve chamber; a diaphragmstructure between said end section and said intermediate section meansarranged to provide a seal with said valve port to admit pressure fluidinto said valve chamber to apply pressure to said diaphragm to provide aseal with said seat, said pilot valve having a second passageway forestablishing communication between said first and second ports toexhaust the fluid from said valve chamber, thereby relieving thepressure on said diaphragm and establishing communication between saidinlet and outlet openings.

9. A valve comprising, one end section having inlet and outlet openingsand a valve seat intermediate said openings; intermediate section meansaligned with said end section to form a valve chamber; a diaphragmstructure between said end section and said intermediate section meanscarrying a renewable disc arranged to provide a seal with said valveseat; a second end section aligned with said intermediate section meansand having a pressure chamber formed therein; means securing said endsections and said intermediate section means together; said intermediatesection means having a port extenda ing therethrough for establishingcommunication between said pressure and valve chambers, saidintermediate section means having a, second port therein for exhaustingpressure fluid from said valve chamber; means for conducting pressurefluid to said pressure chamber; a pilot valve in said pressure chamber,said pilot valve having a passageway adapted to register with said firstport to admit pressure fiuid into said valve chamber to apply pressureto said diaphragm to close the valve, said pilot valve also having aU-shaped exhaust passageway for establishing communication between saidfirst and second ports to exhaust the fluid from said valve chamber,thereby relieving the pressure on said diaphragm and allowing the valveto open.

' DONALD G. GRISWOLD.

